Integrated flight/propulsion control system design based on a centralized approach

Abstract

In this paper, an integrated flight/propulsion control system design is presented for the piloted longitudinal landing task with a modern, statically unstable, fighter aircraft. A centralized compensator based on the Linear Quadratic Gaussian/Loop Transfer Recovery inethodology is first obtained to satisfy the feedback loop performance and robustness specifications. This high-order centralized compensator is then partitioned into airframe and engine "sub-controllers" based on modal controllability/observability for the compensator modes. The order of the sub-controllers is then reduced using internally-balanced realization techniques and the sub-controllers are simplified by neglecting the insignificant feedbacks. These sub-controllers have the advantage that they can be implemented as separate controllers on the airframe and the engine while still retaining the important performance and stability characteristics of the full-order centralized compensator. Command prefilters are then designed for the closed-loop system with the simplified sub-controllers to obtain the desired system response to airframe and engine command inputs, and the overall system performance evaluation results are presented.

Integrated Flight and Propulsion Control - A Review

“…The sub-controllers can then be implemented independently with minimum degradation on performance. A systematic partitioning procedure which largely preserves the performance and robustness properties associated with the centralized controller was first proposed by S.Garg [28]. This method was applied for the VAAC Harrier aircraft IFPC designed using the method of H ∞ loop-shaping.…”